The present invention is directed to a crushing machine including a housing having an inlet for the material to be crushed, a pair of opposite walls forming a part of the housing with a horizontally arranged rotor including crushing tools extending between the opposite walls, and a replaceable outlet grate with grate rods extending parallel to the axis of the rotor and located below the rotor.
A crusher of the general type mentioned above is disclosed and illustrated in U.S. Pat. No. 2,450,492. The grate extends around and below the lower half of the rotor. For maintenance purposes, the grate, made up of parallel rods extending in the axial direction of the rotor, can be removed in halves on rails out of the housing. Apart from the complicated and relatively expensive rail guided arrangement for the grate, the removal of the grate to the sides of the housing involves considerable problems in view of the auxiliary components, such as supply and removal devices, dust removal means, viewing means and supports. Further, adaptation of the grate for a different type of material is not possible with the known grate arrangement.
In German Offenlegungsschrift No. 21 46 362 another crushing machine is disclosed for processing household garbage with a grate located in the lower part of the machine housing. A disadvantage of this known crusher is that for maintenance or repair on the grate or for replacement of the grate in the event there is a change in the type of material being processed, initially the upper housing half must be tilted out of position so that the rotor supported in the lower part of the housing can be removed before the grate is accessible and can be lifted upwardly toward the top of the machine.
This known crusher has both a cumbersome and expensive design. A disadvantageous factor in this known arrangement is that it requires several different operations before the grate can be replaced, that is, opening of the housing, removal of the rotor and the performance of safety measures required in connection with such operations. An adaptation for use with different materials is impossible with this particular crusher.
In U.S. Pat. No. 4,129,260 another crusher arrangement is known having a screen cage which is complicated to disassemble. The screen cage is axially displaceable out of the housing. For the removal of the screen cage out of the housing, however, a housing cover must be removed and at the same time the rotor is supported so that to replace the cover all of the support parts for the rotor must be released. Further, in this arrangement the rotor must be removed. The screen cage is accessible for maintenance only after the rotor is removed. A disadvantageous feature of this complicated and non-adaptable arrangement is, that it is severely limited by the required removal of the rotor supported in the housing cover.